Effects of bacterial endotoxin on the ciliary activity in the in vitro eustachian tube.

We have used a tissue culture technique and a photoelectric method to examine the direct effect of lipopolysaccharide (LPS) on the ciliary activity present in the eustachian tube. Since LPS possesses the major part of the biological activity of endotoxin, our results show clearly that LPS deteriorates the ciliary activity in a dose-response fashion: LPS does not deteriorate the ciliary activity up to 168 h if its concentration is 1 ng/ml or less; 10 ng/ml LPS can cause deterioration of the ciliary activity with extended exposure (more than 96 h); LPS can cause dysfunction of the cilia rather quickly if the concentration is 100 ng/ml or more. Our results show that the ciliary activity in the eustachian tube under clinical conditions can be affected by endotoxin.